Mutual Events of 2003 EL61 and its Inner Satellite
Abstract
The dwarf planet 2003 EL61 is inferred from its photometric modulation to be a rapid rotator with a triaxial shape. Two satellites orbit it, and the astrometric solution of observations from HST and Keck-AO imply that the inner satellite is undergoing mutual eclipses and occultations with the primary (IAUC #8949). We report photometric observations from the 2008 season aimed at detecting these events. Over four months we built up a template (non-event) lightcurve, and we obtained constraining lightcurves on three nights (June 7, June 18, July 14) with predicted events, all with red filters but with a variety of apertures on telescopes distributed in longitude. Combined astrometric and photometric constraints have the potential to yield an albedo map, shape model, and gravitational moments of the primary and the masses and albedoes of the satellites. We discuss the rich mutual-event phenomenology associated with these effects. Taken alone, changes in the viewing direction would end mutual events shortly; however, the non-coplanar orbit of the outer satellite is torquing the orbit of the inner satellite back into an edge-on configuration. Therefore events may last for several more years, presenting an opportunity to probe one of the most exciting objects in the outer solar system.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #40
- Pub Date:
- September 2008
- Bibcode:
- 2008DPS....40.3608F